Hmm, don't sway me over to the other side now, Mark. You know I have a strong dislike for Irréversible...

I haven't seen Irreversible in full, but I don't think I Saw the Devil's main intent is to disturb the viewer. The violence is pretty heavy, but it's exaggerated in a Tarantino-ish way, as seen in that YT clip.

#60-51:

60. The Picture of Dorian Gray (1945)

59. King Kong (1933)

58. Predator (1987)This is universally regarded as an action film for good reason, but I feel that it strongly justifies a place on the list. It contains plenty of great tension inducing moments and a fun series of shocks, not to mention one of the best 'monsters' of cinema. To use a fitting cliche of criticism, it's a thrill ride.

57. Sweeney Todd (2007)People may be put off by this being a musical, but any fan of dark 20's-40's cinema should give it a shot, as Burton's favoritism of expressionistic and Gothic horror influence shines again.

56. I Walked With a Zombie (1943)

55. The Evil Dead (1981)

54. Black Christmas (1974)

53. The Wicker Man (1973)

52. The Devils (1971)It's very difficult to find a decent quality copy of this film now, and due to its controversial themes, it seems that it isn't getting a proper DVD release anytime soon, but it's a great film that's well worth digging for.

51. Vampyr (1932)
A very experimental film for its time with silent film techniques and intentionally marred audio and video, which led to critics of the time panning it. However, over the years it's become widely accepted as one of the greatest and most influential movies of the genre.

50. Aliens (1986)
It opposes the subtlety in pacing and build of the first film, but it's a perfect example of arguably enhancing an already successful subject with creative difference. The action scenes may be too frenetic for those that admired the style of the first film, but they're done in such an entertaining way that few films can pull off.

49. The Haunting (1963)

48. An American Werewolf in London (1981)

47. Misery (1990)

46. Deep Red (1975)

45. Videodrome (1983)Before David Cronenberg made a bigger name for himself with crime dramas, he was commonly associated with the sci-fi horror genre for his brand of 'body horror,' strongly showcased in Videodrome. The unique thing that Cronenberg presents with Videodrome is surrealism. His older films always had plenty of weirdness, but Videodrome had the plot to back up the visuals, making it what I consider Cronenberg's best.

44. Night of the Living Dead (1968)

43. The Invisible Man (1933)
Directed by James Whale (who also directed Frankenstein and The Old Dark House), The Invisible Man is one of the best examples of 1930's horror. Like Frankenstein and Dracula, it molded an early horror icon, but it's also made quite an impression on sci-fi cinema. Though The Invisible Man's historical significance hasn't held up quite as much as the other Universal horror monsters, it did unleash a notable string of sequels (including one that helped launch the career of Vincent Price).

42. Don't Look Now (1973)

41. Angst (1983)
From my review of the film:

Angst is perhaps one of the most disturbing non-exploitation films ever made, and also one of the unsung masterpieces of the 80’s. Because of its content, it never received a theatrical release, but it’s still managed to garner somewhat of a cult reputation over the years.

Another film on the list that's very difficult to come by, but worth looking for.

This is one of my favourite horror films ever and I applaud you for having it on here. Now, I don't think it's a horror flick per se, more of a mystery film with a horror-ish atmosphere. Seriously, the atmosphere created in I Walked With A Zombie is one of the darkest, gloomiest, most-fitting I've ever seen in a film. This can no doubt be attributed fully to Jacques Tourneur and his cinematographer Hunt who expertly use shadows and native island music to create that great atmosphere.

Very good choice here. I love this one myself. This film is very creepy due to the fact that we never actually see the killer. It's almost always more scarier to make the suggestion of ever-present but invisible danger (to the viewer at least) than to have some guy wander around with an axe off-camera for 5 seconds and then show him for 3+ minutes while he brutally slaughters his victim.

This is one of my favourite horror films ever and I applaud you for having it on here. Now, I don't think it's a horror flick per se, more of a mystery film with a horror-ish atmosphere. Seriously, the atmosphere created in I Walked With A Zombie is one of the darkest, gloomiest, most-fitting I've ever seen in a film. This can no doubt be attributed fully to Jacques Tourneur and his cinematographer Hunt who expertly use shadows and native island music to create that great atmosphere.

Agreed, though I'd give much of the credit to Val Lewton as well. Lewton had a good sensibility for the genre at the time and provided a lot of ambition for projects that were made mainly for marketability.

Very good choice here. I love this one myself. This film is very creepy due to the fact that we never actually see the killer. It's almost always more scarier to make the suggestion of ever-present but invisible danger (to the viewer at least) than to have some guy wander around with an axe off-camera for 5 seconds and then show him for 3+ minutes while he brutally slaughters his victim.

A common sentiment, though I think a film can be good either way, depending on circumstance.

#40-31:40. The Body Snatcher (1945)It may not be a popular opinion, but this is my pick for the best Val Lewton horror production. It was the third collaboration between Lewton and a 'pre-Day the Earth Stood Still' Robert Wise. But, the primary reason to watch this is Karloff, who arguably gives the best performance of his career, playing a two-faced psycho.

39. Fists in the Pocket (1965)Uncharacteristically for an early Italian horror film, Fists in the Pocket is purely psychological. It gives off a feeling of uneasiness, but not in an overly ambiguous or surreal way.

38. Let the Right One In (2008)

37. Blood and Black Lace (1964)

One of the most stylish slasher films ever made. Working outside of gothic, period or sci-fi films, one might think that Mario Bava might've been limited stylistically, but his knack for aesthetic atmosphere is just as apparent here. He's more than a one trick pony though; style aside, the film easily stands up with the best of Italian horror.

36. Whatever Happened to Baby Jane (1962)

35. The Tenant (1976)
The most bizarre and likely least approachable of Roman Polanski's 'apartment' trilogy. I don't think it's the best, though it's my preferred of the bunch for its abstractly dreamlike tone, presented in spades during the final 30 minutes.

34. Dead of Night (1945)From my review of the film:

Dead of Night is a series of short horror stories told back to back from the perspective of a room full of strangers that are in a horror story themselves. Sounds boring and perhaps even a bit incoherent, but it is anything but. The film captivates, chills, and above all, entertains.

28. Haxan (1922)This could be one of the principal genre films responsible for inspiring horror-esque imagery. It's actually part fiction, and part documentary, which leads me to believe that the filmmaker's fictional demonstration of witchcraft unintentionally crafted one of the horror genre's best. It's like a creepy old painting come to life.

27. Dracula (1931)

26. Faust (1926)

25. Nosferatu: The Vampyre (1979)Herzog has an extremely distinctive style most of the time. It's usually pretty easy to tell when you're watching one of his films, especially among his earlier works, and Nosferatu is the most characteristic I've seen from him. It strongly showcases his knack for capturing beautiful natural scenery and making it seem almost unnatural, making unnatural scenery seem plainly surreal, and emitting a uniquely dark ambient (the best way to describe this film) tone. There's nothing quite like it, and it's my favorite film Herzog has ever made (which is saying a lot).

24. The Texas Chainsaw Massacre (1974)

23. Dr. Jekyll and Mr. Hyde (1931)From my review of the film:

This version is often thought to be the best adaption of Robert Louis Stevenson’s classic short novel. It’s strange that the version that is so often thought to be the best is beginning to turn into an obscure film, especially when its title is as famous as “Dr. Jekyll and Mr. Hyde.” This semi-obscure masterpiece certainly does deserve much more recognition than it currently receives.

In hindsight, this film isn't nearly as obscure as many of the others on this list, but I do think it should have a more recognizable status compared to Dracula and Frankenstein of the same year.22. The Omen (1976)

21. The Cabinet of Dr. Caligari (1920)
It's pretty apparent merely from looking at some stills from the film, but this is one of the best examples of silent expressionism around, and definitely one of the most renowned for it.

21. The Cabinet of Dr. Caligari (1920)
It's pretty apparent merely from looking at some stills from the film, but this is one of the best examples of silent expressionism around, and definitely one of the most renowned for it.

I still have this film on my computer, albeit the visuals are so poor.

20. The Night of the Hunter (1955)
Being my favorite film, I may be biased towards it, but I think it strongly warrants a place among the best of all time. At the time of release, audiences didn’t react well to a pretty inaccessible style for a 50’s Hollywood film, but I believe it’s gotten better with age.

19. Diabolique (1955)

18. Se7en (1995)

17. Santa Sangre (1989)
An incomparably unique film. Few others pull off surrealism in such a disturbing yet entertaining way.

16. Rosemary's Baby (1968)

15. Kwaidan (1964)

14. The Phantom of the Opera (1925)

13. Evil Dead II (1987)
The king of campy horror films. I can imagine that even the biggest critics of splatter films and video nasties would be hard pressed not to admit that the self-sensible tongue in cheek comedy in Evil Dead 2 is original. Almost everything that made the first Evil Dead great is just magnified in this.